Harrison signed a two-year, $1.4 million contract while Shugg signed a three-year entry level deal.
Last season, Harrison scored three goals and added seven assists for 10 points in 72 games. The stay-at-home blue liner finished the year with a +5 rating.
Shugg, who was drafted in the fourth round last summer, set career-highs with 41 goals and 46 assists for 87 points with the Mississauga St. Michael's Majors of the OHL. He appeared in his third straight Memorial Cup, losing out in the final to the Saint John Sea Dogs.
His first two appearances came with the Windsor Spitfires, winning the title in both years.